固-液搅拌槽内颗粒离底悬浮临界转速的CFD模拟

使用计算流体力学(CFD)软件FLUENT对固-液搅拌槽内颗粒离底悬浮临界转速进行了CFD数值模拟。搅拌槽直径T=500mm，四块挡板均布，搅拌桨为标准六直叶涡轮桨。两相物系为石英砂-水，固体体积分数为5%。文中使用不同的方法作为颗粒离底临界悬浮的判据，推算出颗粒离底临界悬浮转速N_js，计算得出的N_js值和文献数据比较有较好的一致性。同时研究了搅拌槽内的固体浓度分布和固、液两相的速度分布；比较了6个不同搅拌转速下的固体颗粒悬浮状况。

CFD modeling of solids just-suspended impeller speed in stirred tanks

An understanding of the just suspended impeller speed, N js , and the distribution of solids is critical to the efficient operation of industry processes involving solid liquid suspensions. In this paper, the just suspended impeller speed, N js , in solid liquid stirred tank was predicted using CFD and validated against the experimental data obtained from the literature. The multiphase flow was modeled using the Eulerian Granular Multiphase model. Two different criterions were used to predict N js . The CFD predictions are in good agreement with the literature data. Solid concentration distribution and the velocity distribution of solid and liquid were predicted. The performance of solid suspensions under the different agitation speeds was studied.